The position of actuators in position transducer systems in an internal combustion engine is generally ascertained with the aid of a control method as a function of one or more internally or externally predefined setpoint variables. However, manufacturing tolerances as well as environmental influences and aging result in the response of the actuator and of the position transducer system deviating from the expected response or if there are changes in same. The position transducer system to be controlled thus changes as a function of its operating conditions.
In general, a control method should achieve a compromise between all possible states of the actuator, so that the control system achieves a good response with respect to bandwidth, stability, precision and robustness in all operating states. However, adapting the control method and its control parameters to a position transducer having certain properties results in an undesirable system response when the tolerances and the environmental effects on and aging of the actuator become too great and therefore the properties of the position transducer differ too much from those of a position transducer to which the control method and its control parameters are adapted. It is therefore necessary to adapt the control accordingly to achieve an optimal system response over the entire lifetime of the position transducer.
Publication WO 2007/096327 A1 discusses an adaptive control method for a throttle valve in which a pilot control is adapted as a function of measured operating conditions, for example, temperature, air mass flow and pressure drop across a throttle valve.
Publication U.S. Pat. No. 6,668,214 discusses an adaptive control method having online parameter identification. The identified parameters are used to compensate for dead time in the control loop and to adapt a sliding mode controller.